7mm RM neck & shoulder black

Discussion in 'Reloading' started by Tucker943, Sep 24, 2009.

  1. Tucker943

    Tucker943 Member

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    I am new to reloading this year so bear with me. I reload for a Ruger 77 Hawkeye and am struggling to get acceptable accuracy. I put a new trigger in the gun, floated the barrel, and have tried MANY bullets, powders, brass, primers, and COL's and still cannot get consistancy. I'm not trying to build a tack driver here, but am trying to get this rifle to shoot an inch.

    My brass comes out of the action with a black neck and shoulders. When i FL resize it is very bad. When I neck size it isnt as bad but its still filthy. Is this an indication of something i am over looking?
     
  2. kiwi3006

    kiwi3006 Well-Known Member

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    Without seeing any pictures, it can be a sign of too little pressure. The case doesn't expand quickly enough to fill the chamber and some of the gases come back into the chamber.
    I reload for the 7mm mag, black necks by themselves is not really of a concern.
    What load are you using?
    I use 73 gr ADI2217/H1000 fed 215 primer, federal brass and 168 berger.

    Stu.
     
    Last edited: Sep 24, 2009

  3. Tucker943

    Tucker943 Member

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    Let me rephrase part of that. I am tried varying my seating depth a bit. I have only let me COL got to 3.29 I believe.
     
  4. Tucker943

    Tucker943 Member

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    I dont have my notes with me but I have tried tried Nosler 140's with 65g H4350, Nosler 120's with the same powder, Sierra 140 Pro hunters with 63g H 4350, Hornady 162 BTSP's with up to 61g H 4350. I have tried some IMR 4350 with no luck and RL 22. I would need to go back to my book to know exactly what and how much i have tried. Those are a few i have focused on so far that i can remember.
     
  5. kiwi3006

    kiwi3006 Well-Known Member

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    4350 might be a bit fast a powder. Try H4831sc, reloader 22 or H1000, especially with the heavier 160 grain bullets.

    Try doing a search on here for "ladder test" or browse through the reloading or bullets, barrels and ballistic section. There are quite a few detailed threads for working up loads.

    My technique is to start with the bullet just off the lands, work up the charge until i get the velocity i want and then fiddle from there. Adjust powder charge slighty to get the best group, and then adjust seating depth, always seating the bullet deeper.

    Stu
     
  6. J E Custom

    J E Custom Well-Known Member

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    It is not unusual to have some smoking of the neck but if you are also smoking up
    the shoulder then i would have to agree with KIWI about the pressure being to low.

    Mike your necks after firing and then mike a loaded round to see how big the neck
    in your chamber is ( it should not be any larger than .006 thousandths larger than the loaded
    round .If it is then this could be some of the cause.

    One test you can perform is to load the same load using a bullet of the same weight and
    with a cantalure . while loading crimp the bullet in the cantalure and it will tell you if your
    load it weak buy holding the bullet a millisecond longer.

    J E CUSTOM
     
  7. jmason

    jmason Well-Known Member

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    I may be out of line here but those charges look low for 7 mag.
     
  8. hotdog

    hotdog Active Member

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    In my Rem.700 7mm mag. I use 62 grains of IMR 4350 with a 150 gr. Nosler B.T. The OAL Is 3.305 and at 100 yards you can lay a quarter over a 3 shot group. I'm like you I just started reloading a few months back and it took me several trips to the range,with different loads to get these groups.
     
  9. Tucker943

    Tucker943 Member

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    This all makes sense to me now. So if I'm a few grains over max and still need a large boost in pressure I assume that the chamber on the rifle is sloppy as heck....
     
  10. DKA

    DKA Well-Known Member

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    I use 72.5 Gr H 1000 under Nosler 160 Gr Accubonds, with Fed 215 Primers. OAL .040 off the lands.
     
  11. SakoShooterSD

    SakoShooterSD Member

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    I am seeing the same symptoms of burnt powder residue on the neck and shoulder,
    from some rounds fired yesterday at the range with my 7mm Rem Mag.
    (see attached picture).
    7 rounds total fired.
    Some show little or no residue. Some show it down to a line just above the base of the shoulder.

    After the first three shots (one with a different load) the group turned out great: 0.35" for four shots, at 100yds.

    So, is this residue on the shoulder a problem that I need to worry about?
    Is it dangerous?
    (Will it lead to damage to the gun or shooter?)

    These latest loads were done with the following recipe:
    Nosler brass, full-length resized in RCBS dies. This was the fourth firing.
    68.9 gr of Retumbo powder.
    150 gr Barnes TTSX bullet.
    CCI 250 LRM primers.
    COAL 3.290".

    The first rounds fired did not have any mark, but I think that was because there was some leftover lube in the chamber from the previous gun cleaning. The cases had lube on them after extraction. (Yes, I should have run a dry patch through it. Next time I will.)

    Any input would be welcome.
    Thanks.
     

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